Liquid/liquid displacement in a vibrating capillary

Mechanical vibrations can alter static and dynamic distributions of fluids in porous matrices. A popular theory that explains non-destructive changes in fluids percolation induced by vibrations involves elasticity of a solid matrix and compressibility of fluids. Owing to strong damping, elastic and acoustic deformations always remain bounded to narrow zones (a few centimetres) near the source of vibrations. However, field trials prove the existence of the effects that are induced by vibrations in geological reservoirs on a longer scale (100 m). In this study, we develop a non-elastic theory, assessing the time-averaged effects induced by small-amplitude high-frequency vibrations. We examine the immiscible liquid/liquid displacement flows in a capillary (which is a building element of a porous matrix) subjected to translational vibrations. We find that strong-enough vibrations alter the shapes of menisci and change the rates of displacement flows. We find that vibrations slow down or even stop the displacement flows (which is contrary to a common expectation that vibrations help to release fluids from a porous matrix).This article is part of the theme issue 'New trends in pattern formation and nonlinear dynamics of extended systems'.

Automated summary

Mechanical vibrations can affect the distribution of fluids in porous matrices by altering their static and dynamic states. A theory based on the elasticity of solid matrices and compressibility of fluids explains the non-destructive changes induced by vibrations. However, field trials have shown that the effects of vibrations in geological reservoirs can occur on a larger scale than expected. This study focuses on the time-averaged effects induced by small-amplitude high-frequency vibrations and examines the displacement flows of immiscible liquids in capillaries under translational vibrations. The research finds that vibrations can change the shapes of menisci and alter the rates of displacement flows, contrary to the common expectation that vibrations facilitate fluid release from porous matrices.